Shop-Made “Factory Heads”

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Yes, it’s an oxymoron—a factory head is made in a factory, and shop heads are made in the shop—but the truth is, sometimes you can “fake” a factory head in the shop, mostly for aesthetic reasons. All it takes is a flush rivet (an “oops” rivet will do), a round-head squeezer die, a flat die, and a rivet squeezer.

This is a floor panel for our F1 Rocket project. The hinge is for the bottom of the pilot’ seat back. The rivets you see all go into a stiffener that fits between the floor ribs. The two holes on either side (on the extension of the hinge material) will have screws that go into nut plates on the floor substructure. But when the floor panel is removed, those hinge extensions will be flopping around – I wanted them tacked down. But since they have to lay flush on the substructure, I needed a flush rivet head on the bottom.

First, I drilled a #40 hole close to the outboard screw hole location. This will be for our special rivet.
Next, a quick turn of a countersink from the bottom gave me a place to put a flush “oops rivet” – flush head “down”.

Here is the shank of the flush rivet stick up. Sure, I could just squeeze it and have a cylindrical factory head there, but it wouldn’t match the line of round-head rivets on the rest of the hinge material.

With an AD-3 round-head die in the top, and a fat die in the bottom, I squeeze the rivet, forming a “factory-similar” round-head rivet on the top of the workpiece—solely to match the rest of the rivets you can see from the top.
The final result doesn’t exactly match, but it I clearly from the same family of round-head rivets, and hides the little keeper rivet a bit better.

This could also have been a place to do a “double flush” rivet, where you countersink both sides and squeeze the tail flat into a countersink….but the material here was too thin to really make that work. And remember, in this case, it’s not engineering (there is no load on this)… it’s just art!

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Paul Dye
Paul Dye, KITPLANES® Editor at Large, retired as a Lead Flight Director for NASA’s Human Space Flight program, with 50 years of aerospace experience on everything from Cubs to the Space Shuttle. An avid homebuilder, he began flying and working on airplanes as a teen and has experience with a wide range of construction techniques and materials. He flies an RV-8 and SubSonex jet that he built, an RV-3 that he built with his pilot wife, as well as a Dream Tundra and an electric Xenos motorglider they completed. Currently, they are building an F1 Rocket. A commercially licensed pilot, he has logged over 6000 hours in many different types of aircraft and is an A&P, FAA DAR, EAA Tech Counselor and Flight Advisor; he was formerly a member of the Homebuilder’s Council. He consults and collaborates in aerospace operations and flight-testing projects across the country.

2 COMMENTS

  1. I like that your tip has the “look and feel” of the real world — as do your videos. It takes a few months or even years to come to the realization that most of the YT videos and builder website pics rarely display the less than “perfect” project pieces logic would indicate certainly exist.

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